The Spice Girls broke up mainly due to internal tensions, differences, and exhaustion among the members, particularly highlighted by Geri Halliwell's departure in 1998. Geri, known as Ginger Spice, left because she felt disillusioned and exhausted, and there was significant friction between her and the other members, especially Mel B (Scary Spice). Rumors also suggest jealousy and personal conflicts, including an alleged romantic relationship between Geri and Mel B that ended, contributing to the breakup. Additionally, the group's relentless touring and workload led to burnout. After Geri left, the group tried to continue but ultimately could not maintain their earlier success. In summary, the breakup was due to a mix of personal disagreements, exhaustion, jealousy, and changed priorities with solo careers and family commitments influencing the group members over time.